Positive Displacement Pipette Syringe Sensing for Accurate Microdispensing

Solution Overview

Problem

Existing positive displacement pipettes face challenges in accurately dispensing very small liquid volumes without adhering liquid to the pipette tip and require complex syringe retention and ejection mechanisms.

Innovation Solution

A handheld, powered positive displacement pipette with a motorized drive assembly, dispensing solenoid, syringe retention mechanism, and syringe ejection mechanism, allowing for secure, releasable syringe installation, non-contact dispensing, and automatic identification, enabling accurate and repeatable dispensing of sub-microliter volumes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If direct contact between piston and liquid is used in positive displacement pipette, then accuracy is improved, but liquid adhesion to pipette tip occurs causing dispensing errors

Engineering Contradiction:

Core Design Contradiction:

Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The invention extracts the piston from direct contact with the liquid by introducing an air cushion between them. The piston remains in the syringe barrel while the air cushion transmits the displacement force to the liquid at the tip, eliminating liquid adhesion to the piston and tip while maintaining dispensing accuracy.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

An air cushion acts as an intermediary between the piston and the liquid. This air layer transmits the mechanical displacement from the piston to the liquid without direct contact, solving the adhesion problem while preserving the positive displacement mechanism's accuracy for small volume dispensing.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If syringe retention and ejection mechanisms are added to positive displacement pipette, then syringe handling is improved, but device complexity increases

Engineering Contradiction:

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The syringe retention mechanism uses spring-loaded latching elements that automatically engage with the syringe upon insertion and automatically eject the syringe when activated. This self-service approach simplifies operation while minimizing complex manual intervention mechanisms.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The invention replaces complex multi-component mechanical retention systems with a simplified spring-loaded latching mechanism that uses elastic deformation of springs to provide both retention and ejection functions, reducing overall device complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS12616974B2Positive displacement pipette syringe identification system

Publication Date: 2026.05.05

AI summary

Described are exemplary embodiments of a syringe identification system for use with a positive displacement pipette, such as a handheld powered positive displacement pipette. An exemplary syringe identification system may include a sensor, such as a color sensor, that is located at or near a distal end of the pipette and arranged such that the sensor is operative to read an identifying marking(s) on a syringe that has been installed to the pipette. The sensor may be a color sensor having an illumination source and configured to read a color code on the syringe. The color code may be usable to identify the syringe to the pipette.